U.S. patent number 10,022,090 [Application Number 14/057,358] was granted by the patent office on 2018-07-17 for nerve protecting dissection device.
This patent grant is currently assigned to Atlantic Health System, Inc.. The grantee listed for this patent is Atlantic Health System, Inc., a NJ non-profit corporation. Invention is credited to Eric D. Whitman.
United States Patent |
10,022,090 |
Whitman |
July 17, 2018 |
Nerve protecting dissection device
Abstract
The present invention provides an energy based dissection device
that automatically provides a nerve protection function.
Specifically, the present invention operatively connects nerve
monitoring technology and energy based dissection technology to
provide a device that provides energy based dissection
functionality that cannot operate, or operates differently, upon
receipt of real time information from the nerve monitoring
functionality that nerve damage may be imminent in the absence of
such safety shutdown. The present invention also creates a
real-time graphical display of the nerve, including size and
location relative to the energy based dissection device to enable
the operator to safely and accurately avoid damaging the nerve.
Accordingly, the present invention provides a surgical device that
removes human error and reaction time issues which prevent
unintended dissection and concomitant nerve damage.
Inventors: |
Whitman; Eric D. (Mountain
Lakes, NJ) |
Applicant: |
Name |
City |
State |
Country |
Type |
Atlantic Health System, Inc., a NJ non-profit corporation |
Morristown |
NJ |
US |
|
|
Assignee: |
Atlantic Health System, Inc.
(Morristown, NJ)
|
Family
ID: |
52826814 |
Appl.
No.: |
14/057,358 |
Filed: |
October 18, 2013 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20150112325 A1 |
Apr 23, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
5/6877 (20130101); A61B 5/4041 (20130101); A61B
2018/0044 (20130101); A61B 2018/00434 (20130101); A61B
2018/00595 (20130101); A61B 5/4893 (20130101); A61B
2018/00446 (20130101); A61B 2018/00601 (20130101) |
Current International
Class: |
A61B
18/12 (20060101); A61B 5/00 (20060101); A61B
18/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 96/39932 |
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Dec 1996 |
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WO |
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WO 2006/042075 |
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Apr 2006 |
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WO |
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WO 2006/113394 |
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Oct 2006 |
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WO |
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WO 2008/124079 |
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Oct 2008 |
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WO |
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WO 2012/106593 |
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Aug 2012 |
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WO |
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Other References
David W. Eisele, M.D.; Intraoperative Electrophysiological
Monitoring of the Recurrent Laryngeal Nerve; From Laryngyscope 106:
Apr. 1996. cited by applicant.
|
Primary Examiner: Della; Jaymi
Assistant Examiner: Kim; Eunhwa
Attorney, Agent or Firm: The McHattie Law Firm Tyler;
Jonathan A.
Claims
What is claimed is:
1. A surgical apparatus comprising: an energy based dissection
device; a power source for said energy based dissection device; a
nerve integrity monitoring device adapted to detect first energy
signals associated with a selected nerve; a plurality of each of
said plurality of beacons configured to emit a respective energy
pulse having a predetermined frequency, a predetermined duration,
and a predetermined energy level, and to receive second energy
signals associated with the selected nerve; and a processing device
configured to receive first information relating to the first
energy signals, from the nerve integrity monitoring device, and
second information relating to the second energy signals, from the
plurality of beacons, interpret said first information and said
second information, determine whether or not an integrity of
selected nerve is likely to be compromised based on the first
information and second information, and cause a shutoff command to
be automatically transmitted to the energy based dissection device,
when it is determined that the integrity of selected nerve is
likely to be compromised.
2. The apparatus of claim 1 wherein each of said plurality of
beacons is further configured to detect signals associated with
energy pulses emitted by other beacons among the plurality of
beacons.
3. The apparatus of claim 1 wherein each of said plurality of
beacons is further configured to detect additional electrical
signals emitted by said energy based dissection device.
4. The apparatus of claim 3 wherein the processing device further
comprises software configured to utilize data received from said
plurality of beacons to determine a location of the energy based
dissection device relative to each of said plurality of
beacons.
5. The apparatus of claim 1 wherein the processing device further
comprises software configured to utilize data from the nerve
integrity monitoring device to determine a location of the energy
based dissection device.
6. The apparatus of claim 5 wherein said software is further
configured to utilize data from said plurality of beacons to
determine the location of the energy based dissection device.
7. The apparatus of claim 1 wherein the processing device further
comprises software configured to utilize data received from said
plurality of beacons to map a location of nerve tissue.
8. The apparatus of claim 1 wherein the processing device further
comprises software configured to utilize data received from said
plurality of beacons and the nerve integrity monitoring device to
map location of nerve tissue.
9. The apparatus of claim 1 wherein the processing device further
comprises software configured to utilize data received from said
plurality of beacons and predetermined information included in the
software of the nerve integrity monitoring device to map a
real-time location of the energy based dissection device relative
to nerve tissue.
10. The apparatus of claim 1 wherein each of said plurality of
beacons communicates wirelessly with one of the energy based
dissection device and the nerve integrity monitoring device.
11. The apparatus of claim 1 wherein each of said plurality of
beacons is connected via one or more wires to one of the energy
based dissection device and the nerve integrity monitoring
device.
12. The apparatus of claim 9 wherein the nerve integrity monitoring
device is further adapted to generate first vector data and each of
said plurality of beacons is further adapted to generate second
vector data.
13. The apparatus of claim 12 wherein the software interprets the
information supplied by the nerve integrity monitoring device and
each of said plurality of beacons through the use of vector
analysis.
14. The apparatus of claim 1 wherein said energy based dissection
device is configured to emit an energy burst for a predetermined
time, at a predetermined frequency and at a predetermined power
level, said energy burst sufficient in frequency and power level to
be detected by one or more of the plurality of beacons but
insufficient in frequency and power level to damage tissue.
15. The apparatus of claim 1 further comprising a manual override
to the shutoff command.
16. The apparatus of claim 1 wherein a precise location of each of
said plurality of beacons is known by the apparatus.
17. The apparatus of claim 1 wherein a determination that the
information indicates that an integrity of the selected nerve is
likely to be compromised is made based on one of the following: an
EMG response measured by the nerve integrity monitoring device;
radio frequency signals detected by one or more of the plurality of
beacons; energy levels detected by one or more of the plurality of
beacons; the location of the energy based dissection device
relative to a digitally mapped nerve location; the location of the
energy based dissection device relative to one or more of the
plurality of beacons.
18. A surgical apparatus comprising: an energy based dissection
device; a power source for said energy based dissection device; a
nerve integrity monitoring device adapted to detect first energy
signals associated with a selected nerve tissue; a plurality of
beacons, each of said plurality of beacons configured to emit a
respective energy pulse having a predetermined frequency, a
predetermined duration, and a predetermined energy level, and to
receive second energy signals associated with the selected nerve
tissue; and a processing device further comprising software
configured to perform the following steps: receive first
information relating to the first energy signals from the nerve
integrity monitoring device and second information relating to the
second energy signals from the plurality of beacons; determine a
location of the selected nerve tissue based on the first
information and the second information; determine a location of the
energy based dissection device based on the first information and
second information; determine a spatial relationship between the
location of the selected nerve tissue and the location of the
energy based dissection device; determine whether the spatial
relationship between the location of the energy based dissection
device and the location of the selected nerve tissue satisfies one
or more predetermined criteria; and cause a shutoff command to be
automatically transmitted to the energy based dissection device, if
the spatial relationship between the location of the energy based
dissection device and the location of the selected nerve tissue
satisfies the one or more predetermined criteria.
Description
FIELD OF THE INVENTION
The present invention provides an energy based dissection device
that automatically provides a nerve protection function.
Specifically, the present invention operatively connects nerve
monitoring technology and energy based dissection technology to
provide a device that provides energy based dissection
functionality that cannot operate, or operates differently, upon
receipt of real time information from the nerve monitoring
functionality that nerve damage may be imminent in the absence of
such safety shutdown. The present invention also creates a
real-time graphical display of the nerve, including size and
location relative to the energy based dissection device to enable
the operator to safely and accurately avoid damaging the nerve.
Accordingly, the present invention provides a surgical device that
removes human error and reaction time issues which prevent
unintended dissection and concomitant nerve damage.
BACKGROUND
Energy based dissection devices are known. For example, U.S. Pat.
No. 8,241,313 discloses a surgical cutting instrument for use with
a drive motor, and related system and method, is described. The
surgical cutting instrument includes an elongated drive member, a
cutting tip secured to the drive member, a non-conductive coupling
body adapted for connection to a motor assembly, a housing
maintaining the coupling body, a fluid coupling assembly and an
electrical connector for connection to a stimulating energy source.
The electrical connector is in electrical communication with the
cutting tip via an electrical pathway.
In another example, Ethicon Endo-Surgery, Inc. discloses their
HARMONIC ACE.RTM. shears, a sterile, single-patient-use device
consisting of an ergonomic grip housing assembly and two
hand-controlled power settings. The HARMONIC ACE.RTM. shears employ
an adaptive tissue technology enabling the generator to actively
monitor the instrument during use, allowing the system to respond
intelligently to varying tissue conditions. Electrical energy is
converted to mechanical energy.
Nerve monitoring devices are also known. For example, U.S. Pat. No.
7,991,463 discloses systems for determining structural integrity of
a bone within the spine of a patient, the bone having a first
aspect and a second aspect, wherein the second aspect separated
from the first aspect by a width and located adjacent to a spinal
nerve. A stimulator is configured to generate an electrical
stimulus to be applied to the first aspect of the bone. A monitor
is configured to electrically monitor a muscle myotome associated
with the spinal nerve to detect if an onset neuro-muscular response
occurs in response to the application of the electrical stimulus to
the first aspect of the bone. An adjuster is configured to
automatically increase the magnitude of the electrical stimulus to
until the onset neuro-muscular response is detected. Lastly, a
communicator is configured to communicate to a user via at least
one of visual and audible means information representing the
magnitude of the electrical stimulus which caused the onset
neuro-muscular response.
In another example, U.S. Pat. No. 7,972,284 discloses a method of
preventing nerve damage positional injury during surgery includes
providing a nerve damage positional injury pressure monitoring
system including a site sensor with a transducer in the form of a
transducer element and a ring extending outward from the transducer
element, and a monitor connected to the site sensor; adhering the
ring of the site sensor to the patient so that the transducer
element forms a protective barrier in front of the area of the
patient prone to nerve damage positional injury during surgery;
using the system to continuously monitor pressure on the protective
barrier formed by the transducer element in front of the area of
the patient prone to nerve damage positional injury during surgery
with the site sensor and monitor; and causing an alarm to be
actuated to alert medical personnel of a pressure condition when
monitored pressure is greater than a predetermined threshold.
In another example, U.S. Pat. No. 7,214,197 discloses an
intraoperative neurophysiological monitoring system includes an
adaptive threshold detection circuit adapted for use in monitoring
with a plurality of electrodes placed in muscles which are
enervated by a selected nerve and muscles not enervated by the
nerve. Nerve monitoring controller algorithms permit the rapid and
reliable discrimination between non-repetitive electromyographic
(EMG) events repetitive EMG events, thus allowing the surgeon to
evaluate whether nerve fatigue is rendering the monitoring results
less reliable and whether anesthesia is wearing off. The
intraoperative monitoring system is designed as a "surgeon's
monitor," and does not require a neurophysiologist or technician to
be in attendance during surgery. The advanced features of the
intraoperative monitoring system will greatly assist
neurophysiological research toward the general advancement of the
field intraoperative EMG monitoring through post-surgical analysis.
The intraoperative monitoring system is preferably modular, in
order to allow for differential system pricing and upgrading as
well as to allow for advances in computer technology; modularity
can also aid in execution of the design.
In another example, U.S. Pat. No. 7,006,863 discloses a method and
an apparatus for simultaneously assessing the functional status of
component parts of the nervous system by presenting sparse stimuli
to one or more parts of the sensory nervous system. Sparse stimuli
consist of temporal sequences of stimulus conditions presented
against a baseline null stimulus condition, where the non-null
stimulus condition, or conditions, are presented relatively
infrequently. The low probability of encountering a stimulus
differing from a baseline or null stimulus condition in sparse
stimulus sequences insures that gain control mechanisms within the
nervous system will increase the neural response magnitude and also
bias the measured responses to those neurone populations having
such gain controls. The consequently increased response amplitudes
ensure more reliably recorded responses than are obtained with
non-sparse stimuli.
In another example, U.S. Patent Application No. 2010/0145222
discloses a nerve monitoring system [that] facilitates monitoring
an integrity of a nerve.
In another example, Medtronic discloses its NIM-Response.RTM. 3.0
nerve monitoring system, an innovative, intraoperative nerve
integrity monitor enabling surgeons to identify and confirm motor
nerve function and monitor major motor nerves by monitoring
electromyographical (EMG) activity from multiple muscles during
minimally invasive or traditional open surgeries and in response to
a change in nerve function, providing visual and/or audible alerts.
This system also implements artifact detection software for
reducing noise and real-time continuous nerve monitoring with its
APS.TM. Electrode.
There have also been attempts to combine the technology of
dissection devices with nerve monitoring technology. For example,
U.S. Pat. No. 8,050,769 discloses systems and methods for
determining nerve proximity, nerve direction, and pathology
relative to a surgical instrument based on an identified
relationship between neuromuscular responses and the stimulation
signal that caused the neuromuscular responses.
In another example, U.S. Pat. No. 5,928,158 discloses an improved
surgical instrument which is used for cutting of tissue. The
instrument includes a sensor which identifies nerves within the
patient which are proximate to the cutting member of the
instrument. The entire assembly is hand held and includes both a
surgical cutter such as a scalpel blade, scissors, or laser
scalpel, as well as the electronics to stimulate nerves within the
patient. The electronics monitor is positioned near the tip of the
instrument to warn the surgeon of a proximate nerve so that the
nerves are not inadvertently severed. In one embodiment of this
invention, the scissors are incapacitated when a nerve is sensed to
prevent an accidental cutting of the nerve.
In another example, U.S. Patent Application No. 2010/0198099
discloses a signal processing module includes an input module
electronically coupled to a sensing probe of a nerve integrity
monitoring system. The probe senses electrical signals from a
patient during operation of an electrosurgical unit. The input
module receives an input signal from the probe. An EMG detection
module is coupled to the input module and is adapted to detect
conditions in the input signal. The conditions are classified as a
function of a level of electromyographic activity. An output
module, coupled to the EMG detection module, provides an indication
of electromyographic activity in the input signal based on the
detected conditions.
In another example, U.S. Patent Application No. 2014/0267243
discloses a surgical scalpel, scalpel instrument and/or scalpel
system (collectively, scalpel), particularly designed for use in a
transverse carpal ligament surgical procedure, that evaluates an
incision path with respect to a nerve in the incision path, and is
used to perform the incision if appropriate. The scalpel emits an
evaluation signal through a potential incision path through tissue
captured by the scalpel. The scalpel utilizes the emitted
evaluation signal to determine the presence of a nerve in the
incision path. The dissection and evaluation (surgical) instrument
includes a blade that is retractable relative to a target tissue
capture area thereof. Evaluation may include determining the
presence of a nerve before incision and/or the evaluating whether
the target tissue has been appropriately captured. A warning is
provided when the evaluation determines that a nerve is in the
incision path and/or when the captured target tissue is determined
to be inappropriate. Alternatively, the surgical instrument may
disable extension of the blade when the evaluation determines that
a nerve is in the dissection path and/or when the captured target
tissue is determined to be inappropriate.
Therefore, there remains an unmet need for the system and method of
the invention of the present application that operatively connects
nerve monitoring technology and energy based dissection technology
to provide a device that provides energy based dissection
functionality wherein said energy based dissection technology
cannot operate, or operates differently, upon receipt of real time
information from the nerve monitoring functionality that nerve
damage may be imminent in the absence of such safety shutdown and
removing human error and reaction time issues which prevents
unintended dissection and concomitant nerve damage.
SUMMARY
The present invention provides a solution to the unmet need, by
providing an apparatus comprising: a. a connection to: (i) an
energy source capable of powering the apparatus; (ii) an energy
based dissection device; and (iii) a nerve integrity monitoring
device; and b. a communication link between: i. said energy based
dissection device; and ii. said nerve integrity monitoring device
wherein said nerve integrity monitoring device is capable of
monitoring the integrity of a given nerve; iii. wherein said
communication link is capable of receiving information supplied by
said nerve integrity monitoring device and transmitting information
to the energy based dissection device; performing the steps of: 1.
receiving information from said nerve integrity monitoring device;
2. interpreting said information; 3. upon determining a nerve
integrity reading that indicates that nerve integrity will likely
be compromised by continued operation of the energy based
dissection device; 4. transmitting a functional control command to
said energy based dissection device.
There are many alternative embodiments to the device of the present
invention described elsewhere herein.
It will be appreciated by one of skill in the art the many
applications of the device of the present invention and should not
be limited by the examples presented herein. For example, and not
by way of limitation, any type of energy utilized in dissection may
be suitable for use with the device of the present invention.
Similarly, any type of nerve or other tissue capable of its
integrity being monitored through basic electrode conduction may be
suitable for use with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows one embodiment of the present invention. The central
unit (1) receives an input of energy from an energy source (5) to
power all functionality by powering on the central unit with switch
(6). After powering on, the central unit (1) supplies power to the
nerve monitoring device (3) and the energy based dissection device
(2). The nerve monitoring device (3) is connected to the patient
(not shown) according to its normal procedure and provides readouts
(4) indicating nerve integrity. The central unit (1) also receives
information regarding nerve integrity and may adjust or shut off
power to the energy based dissection device (2) according to its
programming. The central unit (1) may also provide an override
switch (7) in order that a surgeon has ultimate decision authority
as to energy flow to the energy based dissection device (2).
FIG. 2 shows one potential readout of a nerve monitoring device in
response to monitoring of a laryngeal nerve during surgery.
FIG. 3 shows another potential readout of a nerve monitoring device
in response to monitoring of a laryngeal nerve during surgery.
FIG. 4 shows another potential readout of a nerve monitoring device
in response to monitoring of a laryngeal nerve during surgery.
FIG. 5 shows another potential readout of a nerve monitoring device
in response to monitoring of a laryngeal nerve during surgery.
FIG. 6 shows an alternative embodiment of the device of the present
invention wherein external beacons (12) are placed in proximity to
the nerve to be monitored (11) wherein said beacons (12) are
capable of monitoring emissions of energy pulses (22) from the
energy based dissection device (2) and reflections thereof.
DETAILED DESCRIPTION
For clarity of disclosure, and not by way of limitation, the
detailed description of the invention is divided into the following
subsections that describe or illustrate certain features,
embodiments or applications of the present invention.
Definitions
An "energy based dissection device" as used herein refers to any
device capable of converting an energy supply into a tool useful
for creating a surgical incision or any type of tissue division or
separation.
An "energy supply" is any form of energy, capable of, and suitable
for, delivering a surgical incision.
A "nerve integrity monitoring device" as used herein refers to any
device capable of monitoring nerve integrity.
"Nerve integrity" as used herein refers to maintaining the normal
functioning of, within accepted medical tolerance limits, nerve
impulse transmission pathways.
A "beacon" is an appropriate energy pulse generator and/or receptor
capable of, in certain embodiments, either or both generating and
receiving energy pulses. In certain embodiments, they may also be
capable of receiving reflections of energy pulses and/or monitoring
characteristics of said pulses.
The System of the Present Invention
In one embodiment the present invention provides an apparatus
comprising: a. a connection to: (i) an energy source capable of
powering the apparatus; (ii) an energy based dissection device; and
(iii) a nerve integrity monitoring device; and b. a communication
link between: i. said energy based dissection device; and ii. said
nerve integrity monitoring device wherein said nerve integrity
monitoring device is capable of monitoring the integrity of a given
nerve; iii. wherein said communication link is capable of receiving
information supplied by said nerve integrity monitoring device and
transmitting information to the energy based dissection device;
performing the steps of: 1. receiving information from said nerve
integrity monitoring device; 2. interpreting said information; 3.
upon determining a nerve integrity reading that indicates that
nerve integrity will likely be compromised by continued operation
of the energy based dissection device; 4. transmitting a functional
control command to said energy based dissection device.
In one embodiment, the present invention would not be merely a
connecting apparatus but would incorporate some or all components
into one unified device.
In one embodiment, the nerve integrity monitoring device would be
combined with the energy based dissection device such that the
nerve integrity monitoring device sensors would be encased within,
and at or near the cutting member of, the energy based dissection
device.
In one embodiment, the functional control command that would be
sent to the energy based dissection device in response to obtaining
a nerve integrity reading that nerve integrity is likely to be
compromised by continued operation of the energy based dissection
device is a shutoff command.
In one embodiment, a shutoff command would have a manual user
override.
In one embodiment, a manual user override would be housed on the
apparatus. In another embodiment, a manual user override would be
housed directly on the energy based dissection device and/or in
close proximity to all other normally utilized surgical controls of
the energy based dissection device.
In one embodiment, a shutoff command would be of a predetermined
length of time. Such length of time would be operator-adjustable.
Alternatively, once a shutoff command is transmitted, an
affirmative signal to enable energy flow restoration to the energy
based dissection device must be manually given by the user.
In one embodiment, the functional control command that would be
sent to the energy based dissection device in response to obtaining
a nerve integrity reading that nerve integrity is likely to be
compromised by continued operation of the energy based dissection
device is a reduction of energy to slow the dissection of the
energy based dissection device.
In one embodiment, a reduction of energy command would have a
manual user override.
In one embodiment, a manual user override would be housed on the
apparatus. In another embodiment, a manual user override would be
housed directly on the energy based dissection device and/or in
close proximity to all other normally utilized surgical controls of
the energy based dissection device.
In one embodiment, a reduction of energy command would be of a
predetermined length of time. Such length of time would be operator
adjustable. Alternatively, once a reduction of energy command is
transmitted, an affirmative signal to enable full energy flow
restoration to the energy based dissection device must be manually
given by the user
In one embodiment, the nerve integrity monitoring device would
perform exactly as it does without the apparatus, i.e., sending
normal visual and/or auditory and/or tactile signals to the user
irrespective of signals that would be sent to the apparatus.
In one embodiment, the device of the present invention would have a
baseline establishment function, wherein the operator could
completely remove any operation of the energy based dissection
device thereby establishing beyond doubt that there could be no
effect of the energy based dissection device on nerve function or
integrity and then pressing a reset button or other similar reset
functionality to establish a new baseline readout from the nerve
integrity monitoring device.
In one embodiment, the device of the present invention would have
controls to adjust detection sensitivity threshold based on initial
baseline parameters.
In one embodiment, the device of the present invention would
provide a test pulse function, wherein the operator would be able
to deliver a short duration lower energy burst from the energy
based dissection device to an area where it may be thought to be at
risk to test the area and review any change in readout from the
nerve integrity monitor device prior to delivering a full energy
cutting function. Such functionality could be implemented by
including an energy dial to reduce the energy delivered to the
energy based dissection device or a button that would automatically
deliver a predetermined lower energy burst for a predetermined time
period through the energy based dissection device before restoring
the energy to normal power. The test pulse would be operator
adjustable for energy strength and time of duration.
In one embodiment, the device of the present invention would have
all functionality switches and buttons allowing operator chosen
commands to be placed on the floor to be operated by foot allowing
the operator full hand availability for operating procedures. Such
foot controls could be hard wired or connected wirelessly to the
device of the present invention.
Energy based dissection devices have become commonplace in the
modern operating room as a result of their improved efficiencies
and precision.
For example, Medtronic provides the PlasmaBlade.TM. which are a
family of disposable cutting and coagulation devices that offer the
exacting control of a scalpel and bleeding control of traditional
electrosurgery without extensive collateral damage. The
PlasmaBlade.TM. is based on pulsed plasma technology which
represents an advancement of radiofrequency surgical
technologies.
In another example, Covidien provides the Sonicision.TM., a
cordless ultrasonic dissection device. Covidien advertises that its
Sonicision.TM. device results in "faster dissection than the
Harmonic.TM." device (referring to the Ethicon Harmonic Ace.TM.
device referenced elsewhere herein).
In another example, Covidien provides a portfolio of energy based
dissection devices under the ForceTriad.TM., Valleylab.TM. and
LigaSure.TM. brands employing a variety of technology including
monopolar and bipolar electrosurgery components.
Generally, electrosurgery refers to the cutting and coagulation of
tissue using high-frequency electrical current. Electrical current
is created by the movement of electrons and voltage is the force
that creates this movement. There are two types of electrical
current--direct current (DC), where the electrons always flow in
the same direction, and alternating current (AC), where the current
changes direction periodically. With AC, each time the current
reverses, it is considered one cycle. Frequency refers to the
number of cycles in one second and is measured in hertz (Hz).
Basic electrosurgery units used in operating rooms convert standard
AC frequencies, i.e., 50 Hz to 60 Hz as delivered from a typical
wall outlet to much higher frequencies such as from 500,000 Hz to
3,000,000 Hz. This is necessary to minimize nerve and muscle
stimulation, which occurs at frequencies below 10,000 Hz.
Basic electrosurgery units are subject to electromagnetic
interference, either interruption of their normal operating
parameters by other instruments generating a nearby electrical
field or interfering with the normal operation of other nearby
instruments.
Certain non-electrical energy based dissection devices may overcome
this interference. Examples include, but are not limited to,
ultrasonic energy based dissection devices and thermal energy based
dissection devices.
All of these devices have some type of thermal and/or electrical
spread, i.e., the surgeon intends to cut through a specific tissue
and at least a minimal amount of adjacent tissue is affected. The
key is to minimize the spread so that a minimal amount of adjacent
tissue is affected with unintended consequence. Of significant
importance is when such adjacent tissue is nerve tissue.
Another consideration is interference with intra-operative
monitoring equipment. Responses have included functionality that
includes argon beam coagulation, lasers, ultrasound, saline
enhancement and ferromagnetic technology for minimizing the need
for actual electric current passing through tissue.
Nerve integrity monitoring devices have also become commonplace in
the modern operating room where certain surgeries place at risk
damage to significant nerve tissues.
For example, Medtronic's NIM-Neuro.RTM. 3.0 nerve integrity
monitoring system provides an eight-channel nerve monitoring system
delivering advanced monitoring features such as simultaneous
monitoring during bipolar cautery, real-time continuous monitoring
with an APS.TM. electrode, artifact detection software to help
reduce noise, signal overlay in a microscope, use of two
stimulators at one time, touchscreen operation, and audio and
visual alerts.
In another example, Natus.RTM. Neurology provides the XLTEK
Protektor 32.TM. IOM system with multimodality monitoring,
configurable stimulus interleaving, nerve integrity monitoring mode
to identify neural structures and confirm efferent nerve function
and selectable stimulator contact chimes.
In another example, NuVasive.TM. provides its NVM5.RTM. nerve
monitoring system for real-time, precise and reliable feedback to
ensure nerve and spinal cord safety. By using this unique and
advanced technology, the surgeon is provided with intraoperative
information about the location and function of the nerves.
In all of the foregoing examples, the surgeon is provided
information, either in the form of an audible or visual signal or
some type of wave readout that must be first received and then
understood prior to the surgeon reacting. Thus, there is room for
surgeon error in interpretation as well as reaction time issues in
utilizing the existing nerve monitoring technology.
In one embodiment, the device of the instant invention provides an
apparatus wherein any one of the foregoing examples of energy based
dissection devices or some other equally suitable energy based
dissection device is connected to the apparatus such that the
apparatus delivers, with the capability to control, the flow of
energy to the energy based dissection device. Alternatively, the
energy based dissection device may be powered separately and the
apparatus is merely capable of interrupting and/or altering the
flow of energy to the energy based dissection device.
In one embodiment, the device of the instant invention provides an
apparatus wherein any one of the foregoing examples of nerve
integrity monitoring devices or some other equally suitable nerve
integrity monitoring device is connected to the apparatus such that
the apparatus is capable of receiving information from the nerve
integrity monitoring device. The apparatus may power the nerve
integrity monitoring device or the nerve integrity monitoring
device may be powered separately.
In one embodiment, the device of the instant invention provides an
apparatus which, upon receiving information from the nerve
integrity monitoring device, is capable of interpreting the
information received to determine if nerve integrity is likely to
be compromised by continued exposure to levels of energy that
triggered the reading in the first instance.
In one embodiment, the device of the instant invention provides an
apparatus that upon interpreting information that nerve integrity
is likely to be compromised, is capable of delivering an
appropriate command to the energy based dissection device. An
appropriate command may be one that simply shuts off energy to the
energy based dissection device. Another appropriate command may be
one that reduces the flow of energy to the energy based dissection
device.
Nerve integrity monitoring devices typically provide functionality
by providing electrodes that are in functional contact with a nerve
to be monitored. The nerve integrity monitoring devices can then
detect whether the nerve at issue is functioning normally and
providing an unbroken circuit or if the nerve has been damaged and
cannot complete the circuit normally.
In FIG. 2, the wave readouts demonstrate that the nerve at issue
(in this case a recurrent laryngeal nerve ("RLN") which is at risk
in thyroid, parathyroid and other surgeries performed close to the
course of the RLN) is functioning as expected when an external
stimulus is present.
In FIG. 3, the wave readouts (again, in the case of an RLN)
similarly demonstrate expected functionality. The differences
between FIGS. 2 and 3 reflect the differences in stimuli, the
actual proximity to the RLN (i.e, direct contact versus immediate
proximity), the specific location along the RLN that the stimulus
occurs, and the like.
In FIG. 4, the wave readouts (again, in the case of an RLN)
demonstrate an RLN that is experiencing nearby or indirect stimulus
(traction and/or physical trauma).
In FIG. 5, (again, in the case of an RLN), the top wave readout
indicates an RLN that is undisturbed, while the bottom wave readout
indicates an RLN that is undisturbed for a period of time and then
indicates a stimulus of expected RLN functionality.
Reference to the foregoing figures demonstrate that a variety of
wave readouts are possible based upon many factors such as the
actual nerve to be monitored, the strength of the energy wave of
the energy based dissection device, the method of monitoring nerve
integrity and actual proximity to the nerve of the energy based
dissection device when an energy pulse is delivered.
One of skill in the art will appreciate that where all other
variables are constant and/or predetermined and accurately measured
and controlled, the actual and/or relative proximity to the nerve
to be monitored may be determined by interpreting the nerve
monitoring device wave readouts.
This nerve proximity monitoring function can be implemented to
create a nerve mapping function based on interpreting data gathered
simultaneously from multiple electrodes at various points along a
particular nerve, and/or from mathematical vector analysis of the
nerve monitoring waveform resulting from single or multiple energy
stimuli.
Each time a nerve senses an electrical impulse, it reacts in a way
that provides a specific wave readout in the nerve monitoring
device. As noted, these wave readouts can be interpreted to provide
a shutoff command to the energy based dissection device when such
device is so close to the nerve to be monitored that continued
supply of energy is likely to damage the nerve integrity. Such
readouts can also be used to determine nerve proximity and nerve
mapping. By continuously determining such nerve proximity, changes
in proximity can be measured and create a vector mapping of nerve
location and orientation. By sensing against predetermined areas
along a nerve, three dimensional nerve mapping can be accomplished.
By plotting this information against known nerve structure, an
accurate indication can be determined of likely nerve location,
size and orientation in relation to the current location of the
energy based dissection device. The more readings that are
obtained, the more accurate this nerve location plotting can
be.
Inherent in the waveform readouts from a nerve integrity monitoring
device are vector data. A vector is a quantity that has both
direction and magnitude. Nerves function by conducting energy along
its length, i.e., the nerve integrity is measured by the magnitude
and direction of such energy conduit. A given nerve is generally
known in terms of its size, shape, ability to conduct energy and
relative location within any particular patient based on that
patient's age, size, condition and other criteria. Based on a
library of a multitude of prior readings from subjects similar to a
given patient and a baseline reading from the specific patient,
mathematical vector analysis on the vector data contained within
given waveform readouts can be used to project an accurate
real-time mapping of the given nerve relative to the location of
the energy based dissection device. As the operator moves the
energy based dissection device, the relative distance from it to a
given point along the given nerve changes. This new data, also
containing vector data, is used to continuously update and refine
the relative location of the given nerve to the energy based
dissection device. For example, a given nerve of a given size and
condition will be expected to generate a waveform of certain
characteristics within tolerance limits in response to stimuli of a
given energy pulse at a certain distance. Moreover, that nerve will
be known to exist generally in size and location within a patient
and to conduct energy in a certain direction. The operator can
establish a baseline by providing a known energy pulse at a known
distance to a specific nerve in an area where such movements and
locations can be readily observed. Once these initial readings are
established and comport with expected values, then, as the operator
moves into the surgery, all waveforms will be analyzed against
these known parameters. One of ordinary skill in the art will
appreciate that using vector data analysis, an accurate plot of the
actual nerve size and location relative to the energy based
dissection device can be performed.
In one embodiment, the nerve integrity can be monitored along
multiple points of its trajectory, and/or through vector analysis
of the waveform. Thus, when the energy based dissection device
sends out an energy pulse, multiple wave readouts ensue
simultaneously, each bearing specific characteristics, including
vector data, based upon the proximity of that particular sensor
point to the energy based dissection device. Thus, the plotting of
the nerve location and orientation with respect to the energy based
dissection device can be even more accurate.
In one embodiment, this nerve location and orientation is plotted
in real time on a graphical display on the device of the present
invention.
In one embodiment, nerve location and orientation information can
be supplemented with information beacons. In one embodiment,
beacons capable of delivering energy pulses can be placed in situ
into nearby soft tissue and held in place with prongs prior to
beginning a surgical procedure. The beacons could be wireless or
connected to either the energy based dissection device or the nerve
integrity monitoring device or a separate communicatively connected
functional apparatus within the device of the present invention
with wires. Such beacons would emit a known energy pulse at various
known frequencies and duration to be received by the electrodes
monitoring nerve integrity. In this manner, the nerve size,
location, orientation and integrity can be monitored relative to
the beacon pulses prior to any energy pulse generated by the energy
based dissection device in all of the same ways as just discussed.
Then, when the energy based dissection device is introduced into
the equation, the known energy being introduced by said device is
compared to the readings obtained by the beacon pulses. In this
manner, information will be generated to determine the proximity of
the beacons to the nerve and with greater accuracy, the proximity
of the energy device to the beacons and thus, the nerve.
In one embodiment, the beacons could also receive energy signals
and detect the nerve data independent of and in addition to the
nerve integrity monitoring device, and also detect the energy based
dissection device. The nerve integrity monitoring device is still
needed to monitor actual nerve integrity. However, the additional
information gathered from reflected energy pulses between the
beacons and the nerve and the energy based dissection device and
the beacons will yield greater accuracy of nerve location, size,
and orientation.
EXAMPLES
For clarity of disclosure, the following examples are based on a
typical thyroid surgery procedure that potentially harms the RLN.
One of ordinary skill in the art will appreciate the many
embodiments of the system of the present invention, for example,
and not by way of limitation, back or spinal surgery, surgery
proximate to the optic nerve, surgery proximate to the brain stem,
and the like.
In a typical thyroid surgery, RLN injury is a dreaded potential
complication because surgical cutting devices usually operate in
close proximity to the RLN during surgery. With the advance of
surgical cutting devices, including the use of energy based
dissection devices, the cutting (and other unwanted trauma) can
happen in an instant.
Mechanisms of RLN injury may include transection, stretch/traction,
crush, ligature entrapment, electrical, thermal, and ischemia.
Factors that increase risk of RLN injury may include re-operation
to correct an issue, non-identification of the RLN, inexperience,
variances in anatomy, or other unexpected variables such as goiter
size and location.
Any device that can minimize these risk factors is desirable.
The early devices and methods aimed at reducing risk include
devices to identify and monitor RLN integrity.
For example, use of hook-wire electrodes placed endoscopically into
the thyroarytenoid muscles to track ongoing EMG over continuously
updated sampling epochs.
In another example, subdermal electrodes are endoscopically placed
bilaterally into the posterior cricoarytenoid muscles.
However, there are disadvantages of intramuscular EMG electrode
placement such as, such placement is "blind" and subject to
dislodgment.
Surface electrodes have been implemented. An example is an
electrode consisting of paired silver flexograph plates attached to
a polyethylene base, which is curved to conform to the postcricoid
area.
Advances now include the use of an EMG endotracheal tube consisting
of a low-pressure cuffed silicone elastomer tube with integrated
bilateral paired 0.16 inch diameter stainless steel wire electrodes
that run in protective channels along the tube and are exposed for
30 millimeters at the glottis lovel and skewed anterolaterally for
vocal cord contact and provides for continuous tracking of EMG
activity.
Once anesthesia is induced, the endotracheal tube is placed such
that the vocal cord is in true contact with the exposed electrodes.
Baseline stimulation is recorded to insure identification of the
RLN and recognition of an event that causes such stimulation. The
surgery is then conducted. After the surgical specimen is removed,
the RLN is again stimulated to insure post procedure integrity.
If, during the surgery, the surgeon recognizes a stimulus pattern
(such as those indicated in FIGS. 2-4) wave readout from the nerve
integrity monitoring device, he knows that he is stimulating the
RLN and needs to cease doing whatever it is that he was doing at
that moment and re-establish a safe operating pathway.
Other surgical advances include the use of energy based dissection
devices, such as those described above. They provide for near
instantaneous dissection along a surgical path. The danger is that
if that surgical path erroneously is an unsafe operating pathway,
damage can be done to the RLN prior to the ability of the surgeon
to recognize a stimulus pattern (such as those indicated in FIGS.
2-4) that indicates inadvertent stimulus resulting in damage to the
RLN.
The device of the present invention provides a way to eliminate
surgeon reaction time and surgeon error in recognition by providing
a device that receives the wave readout information in real time
and simultaneously interprets such wave readouts and upon
interpreting a readout that indicates any potential damage to the
RLN, cuts power to the energy based dissection device such that
even if the surgeon does not have time to react, the RLN will cease
being stimulated.
This will give time to the surgeon to consider his pathway,
identify potential damage, and restart the procedure prior to any
damage to the RLN occurring.
One of skill in the art will appreciate the type of interpretative
analysis needed in connection with any specific wave readout or
other form of signal generated by nerve integrity monitoring
devices and what immediate response is necessary to protect RLN (or
other nerve, in the case of other types of surgeries to which this
device is applicable) functionality.
One of skill in the art will also appreciate if full shutoff of
energy to the energy based dissection device is required or if
allowable to proceed at reduced on a minimal stimulus reading.
Similarly, it may be desirable to have a manual override to
continue with a procedure despite the risk disclosed. Surgeon
expertise is not impacted, but rather enhanced by providing
potential error correction and reaction time assistance.
Publications cited throughout this document are hereby incorporated
by reference in their entirety. Although the various aspects of the
invention have been illustrated above by reference to examples and
preferred embodiments, it will be appreciated that the scope of the
invention is defined not by the foregoing description but by the
following claims properly construed under principles of patent
law.
Each and every feature described herein, and each and every
combination of two or more of such features, is included within the
scope of the present invention provided that the features included
in such a combination are not mutually exclusive.
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